| The traditional transaction processing model, though useful in database systems, does not perform well in many specialized applications. Researchers have addressed this problem by proposing various advanced transaction models. The advanced transactions are characterized by having a number of cooperative subtransactions whose execution is controlled by dependencies . There is few research work on unified transaction model and the analysis for correct specification of dependencies. The issues like dependency conflicts and redundancies are not addressed. For instance, dependencies can conflict with each other. A pair of conflicting dependencies will require contradicting operations in execution, and will in turn lead to deadlock and denial-of-service problems.; Moreover, existing work does not specify how to enforce dependencies and ensure the correct execution of advanced transactions. The dependencies pose new challenges which must be addressed in execution. A reliable scheduler is needed to ensure satisfaction of all dependencies in execution. In case of system crash, the system will be left in inconsistent state. We need effective failure recovery techniques, not only to restore the data items to consistent states, but also to preserve the dependencies. Malicious attacks cannot be prevented all the time. Correct and complete damage assessment are crucial for survivability of advanced transactions.; In this dissertation, I proposed a reliable transaction processing model for advanced transactions. It can be used to develop complex and powerful advanced transactions correctly and uniformly, and more important, it will be reliable in execution and have the power to survive system crashes and malicious attacks. |
